Pneumatic control system and method

ABSTRACT

This disclosure relates to a pneumatic control system for a fuel burning apparatus wherein the pneumatic source for actuating an actuator to interconnect the fuel source to the burner means is only created after an electrical ignition means for the burner means has reached ignition temperature. In addition, the conduit means leading from the pneumatic source to the pneumatically operated actuator means has an opening means therein which is only closed after the ignition means reaches its ignition temperature.

United States Patent Palmer et al.

PNEUMATIC CONTROL SYSTEM AND METHOD Inventors: Reed A. Palmer; Raymond J. Fox, both of Glendale, Calif.

Assignee: Robertshaw Controls Company,

Richmond, Va.

Filed: July 27, 1970 Appl. No.: 64,079

Related US. Application Data Continuation of Ser. No. 772,642, Nov. 1, 1968, abandoned.

US. Cl ..43l/6, 431/66 Int. Cl ..F23ll 5/22 Field of Search ..43 H6, 66; 236/15 51 Mar. 14, 1972 [56] References Cited UNlTED STATES PATENTS 3,384,071 5/1968 Body et al. ..l26/273 X 3,457,020 7/1969 Hine Primary Examiner-Edward G. Favors Attorney-Auzville Jackson, .lr., Robert L. Marben and Candor, Candor and Tassone [57] ABSTRACT This disclosure relates to a pneumatic control system for a fuel burning apparatus wherein the pneumatic source for actuating an actuator to interconnect the fuel source to the burner means is only created after an electrical ignition means for the burner means has reached ignition temperature. In addition, the conduit means leading from the pneumatic source to the pneumatically operated actuator means has an opening means therein which is only closed after the ignition means reaches its ignition temperature.

20 Claims, 4 Drawing Figures PAIENTEB MR 1 4 I972 SHEET 1 BF 3 8 w 5 7. 6 7 9 %2 3 7 5 M g A r in 3 Q I, U u R% w w m WW I 6 L $8 5X LI 3 2 3 6 V R7 1 v 1 a 9 w m 5 5 9:. LL% B W M 5 8 v W ,1 4 :4 I. 7- )Q U a 6 l T .Q I o Q o I 1 O .n l 9 O 2 u 3 2 H 0 L b. 6 o .1 2 8 O W u 2 o L U n m 0 l H w A W H m a 1 q w M Ma l 2 K 9 INVENTORS REED A.PALMER RAYMOND J. FOX

PATENTEDHAR 14 m2 3549.154

SHEET 2 BF 3 lOl 93 99 9 96 94 I 90 97 as FIG.2

F F |O4 "I03 ENTORS RE A. PALMER RAYMOND J. FOX

PATENTEUMAR 14 I972 SHEET 3 UF 3 IZA OOOOOOOOO INVENTORS REED A. PALMER RAYMOND J. FOX

PNEUMATIC CONTROL SYSTEM AND METHOD This is a continuation of Ser. No. 772,642 filed Nov. 1, 1968 and now abandoned.

This invention relates to an improved pneumatic control system for a fuel burning apparatus or the like as well as to an improved method for controlling such a fuel burning apparatus or the like.

It is well known that a fuel source can be interconnected to a burner means of an apparatus by interconnecting a pneumatic source to a pneumatically operated valve means disposed in the fuel source conduit.

However, one of the features of this invention is to prevent the creation of the pneumatic source for actuating the pneumatically operated valve means until after an electrical ignition means for the burner means reaches its ignition temperature in a manner to substantially insure that ignition will occur at the burner means.

Another feature of this invention is to provide an opening means in the conduit means that leads from the pneumatic source to the pneumatically operated valve means in such a manner that the opening means will prevent operation of the pneumatically operated valve means even if the pneumatic source is operating until such opening means is closed, the closing of such opening means only taking place after the ignition means for the burner means has reached its ignition temperature.

One embodiment of this invention for producing the above feature comprises a system wherein pneumatically operated actuator means are adapted to interconnect a source of fuel to the burner means when a pneumatic source is interconnected to the actuator means, the system having an electrically operated pneumatic pump and an electrically operated ignition means for the burner means interconnected together in an electrical circuit in such a manner that when the ignition means is initially energized, the electrically operated pump is shunted from the electrical circuit by a flame sensing electrical switch so as to prevent operation of the pneumatic pump. However, when the flame switch senses that the ignition means is at ignition temperature, the flame switch opens and places the electrical power source across the pneumatic pump to cause operation thereof for opening the pneumatically operated valve means in the fuel source conduit. In addition, the flame switch, when opening to energize the pneumatically operated pump, operates a valve member which will close an opening means in a conduit means leading from the pneumatically operated pump to the pneumatically operated valve means so as to permit opening of the valve means.

Accordingly, it is an object of this invention to provide an improved pneumatically operated fuel control system having one or more of the novel features set forth above or hereinafter shown or described.

Another object of this invention is to provide an improved method of operating such a control system or the like.

Other objects, uses, and advantages of this invention are apparent upon a reading of this description which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIG. 1 is a schematic view illustrating the improved fuel control system of this invention with certain parts thereof being illustrated in cross section.

FIG. 2 is an enlarged cross-sectional view illustrating one of the control components of the system of FIG. 1.

FIG. 3 is a view similar to FIG. 2 and illustrates the flame sensing switch means of the control system of FIG. 1.

FIG. 4 is a view similar to FIG. 1 and illustrates another embodiment of the fuel control system of this invention.

While the various features of this invention are hereinafter illustrated and described as being particularly adapted for providing a pneumatically operated fuel control system for a domestic laundry dryer or the like, it is to be understood that the various features of this invention can be utilized singly or in any combination thereof to provide a control system for other types of apparatus as desired.

Therefore, this invention is not to be limited to only the embodiments illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.

Referring now to FIG. 1, the improved pneumatically operated fuel control system of this invention is generally indicated by the reference numeral and comprises a main burner means 11 adapted to be interconnected to a fuel source conduit 12 by a conduit means 13 that is separated from the fuel source conduit 12 by a first valve seat 14, the first valve seat 14 being, in turn, separated from the conduit 13 by a second valve seat 15. In addition, the conduit 13 has a valve seat 16 downstream from the valve seat and in advance of the burner means 11 to be controlled by a shaft-like valve member 17 in a manner hereinafter described to provide modulated fuel flow to the main burner means 11.

The first valve seat 14 is controlled by a pneumatically operated actuator 18 that comprises a housing means 19 having its open end 20 closed by a flexible diaphragm 21 that carries a valve member 22 for opening and closing the valve seat 14 while cooperating with the housing member 19 to define a chamber 23 therebetween. A compression spring is disposed in the chamber 23 and normally tends to urge the flexible diaphragm 21 downwardly in FIG. 1 so that the valve member 22 seats against the valve seat 14 to disconnect the fuel source conduit 12 from the valve seat 15.

Similarly, the valve seat 15 is controlled by another pneumatically operated actuator 25 that comprises a cup-shaped housing member 26 having its open end 27 closed by a flexible diaphragm 28 that carries a valve member 29 for opening and closing the valve seat 15 and cooperating with the housing member 26 to define a chamber 30 therebetween. A compression spring 31 is disposed in the chamber 30 to normally tend to urge the flexible diaphragm 28 downwardly in FIG. I to maintain the valve member 29 against the valve seat 15 to also prevent the fuel source conduit 12 from being interconnected to the conduit 13.

Another pneumatically operated actuator 32 controls the position of the shaft valve member 17 relative to the valve seat 16 and comprises a cup-shaped housing member 33 having its open end 34 closed by a flexible diaphragm 35 that is secured to the shaft-like valve member 17 and cooperates with the housing 33 to define a chamber 36 therebetween. A compression spring 37 is so constructed and arranged about the valve member 17 that the same tends to move the flexible diaphragm 35 to the right in FIG. I to hold the valve member 17 in its fully opened position relative to the valve seat 16.

An electrically operated vacuum pump 38 is provided for the system 10 and has its inlet side 39 interconnected to a conduit 40 that is fluidly interconnected to a pair of conduits 41 and 42, the conduit 41 being disposed in fluid communication with the chamber 23 of the actuator 18 while the conduit 42 is disposed in fluid communication with the chamber 30 of the actuator 25. However, the conduit 42 has a first opening means 43 therein interconnecting the conduit 42 to the atmosphere and a second opening means 44 therein also interconnecting the conduit 42 to the atmosphere for a purpose hereinafter described.

The outlet side 45 of the vacuum pump 38 is interconnected by a conduit 46 to the chamber 36 of the actuator 32 as well as to a branch conduit 47 that has an open end 48 adapted to have the effective side of the opening 48 thereof controlled by a valve member 49 carried on a temperature sensing bimetal member 50 that is adapted to sense the temperature output effect of the burner means 11 for a purpose hereinafter described.

The control system 10 of this invention includes an electrical circuit means that is generally indicated by the reference numeral 51 in FIG. 1 and comprises a pair of power source leads L and L respectively adapted to be interconnected to points 52 and 53 by lead means 54 and 55 when the control system 10 is required to operate the burner means 11. Therefore, the particular details of the electrical circuit 51 between the power source leads L and L and the points 52 and 53 need not be described as the same is conventional in the art for a clothes dryer whereby only the parts of the circuit 51 to the right of points 52 and 53 in FIG. 1 need be described in order to understand the various features of this invention.

Three electrical switch means 56, 57 and 58 are provided for the electrical circuit means 51 with the electrical switch means 56 having a conductive bimetal switch blade 59 provided with one end 60 that is secured from movement and is electrically interconnected to the point 53 by a lead 61. The cantilevered end 62 of the bimetal blade 59 carries an electrical contact 63 normally disposed in electrical contact with a contact 64 that is interconnected by a lead 65 to one side ofa ceramic igniter coil 66, the other side of the igniter or ignition means 66 being interconnected by a lead 67 to the secured end 68 of a conductive bimetal member 69 of the electrical switch means 58.

The free or cantilevered end 70 of the bimetal member 69 carries an electrical contact 71 adapted to normally be disposed against an electrical contact 72 that is interconnected by a lead 73 to the point 52 of the circuit 51, the lead 73, in turn, being interconnected by a lead 74 to one side 75 of the electrically operated vacuum pump 38. The other side 76 of the electrically operated vacuum pump 38 is interconnected by a lead 77 to the lead 67.

The bimetal member 69 of the electrical switch means 58 carries a valve member 78 that is adapted to move in unison with the free end 70 thereof to open and close the opening 44 in the conduit 42 in a manner hereinafter described.

An electrical heater 79 is provided for the switch means 56 and has one side thereof interconnected by a lead 80 to the lead 61 while the other side thereof is interconnected by a lead 81 to one side of another electrical heater 82 provided for the switch means 57. The other side of the electrical heater 82 is interconnected by a lead 83 to the lead 67.

A conductive bimetal member 84 is provided for the electrical switch means 57 and has one end 85 thereof secured from movement and being electrically interconnected by a lead 86 to the lead 81. The free end 86 of the bimetal member 84 carries an electrical contact 87 normally disposed spaced from an electrical contact 88 that is interconnected by a lead 89 to the lead 83. The bimetal member 84 carries a flexible blade 90 to move in unison therewith with the flexible blade 90 carrying a valve member 91 for opening and closing the opening means 43 in the conduit means 42 in a manner hereinafter described.

Thus, it can be seen that the bimetal switch blade 59 of the switch means 56 is sensitive to the temperature of the electrical heater means 79 while the bimetal switch blade 84 of the electrical switch means 57 is sensitive to the temperature of the electrical heater 82. However, the bimetal member 69 of the electrical switch means 58 is sensitive to the temperature of the ignition means 66 as well as to flames at the main burner means 11 in a manner hereinafter described.

While the electrical switch means 57 can be constructed and arranged in any suitable manner to operate in a manner hereinafter described, reference is now made to FIG. 2 wherein one embodiment of the electrical switch means 57 is illustrated and comprises a housing means 92 provided with terminals 93 and 94 to be respectively interconnected to the leads 86' and 89 of the circuit 51 previously described, the terminal 93 being electrically interconnected to the electrical heater 82 by a terminal post means 95 as well as to the secured end 85 of the bimetal blade 84. In turn, the terminal 94 is interconnected to the stationary contact 88 by terminal post means 96. The previously described opening means 43 in the conduit means 42 can comprise a valve seat 97 formed on a nipple means 98 threaded in a threaded opening 99 in the housing means 92 of the switch means 57 with the valve seat 97 being adapted to be opened and closed by the valve member 91 carried by the flexible blade 90 having its left hand end 100 secured to the left hand end 85 of the bimetal member 84 by the terminal post means 95. A passage means 101 through the nipple means 98 is adapted to be disposed in fluid communication with the conduit 42 whereby when the valve member 91 is disposed in the open position of FlGS. 1 and 2, the atmosphere is interconnected to the conduit 42.

However, when the heater means 82 is energized in a manner hereinafter described, the bimetal member 84 warps upwardly in FlGS. l and 2 to not only place the electrical contact 87 against the electrical contact 88, but also to place the valve member 91 in seating engagement with the valve seat 97 so as to close the opening 43 in the conduit 42 for a purpose hereinafter described.

Similarly, while the electrical switch means 58 can be formed in any suitable manner to perform the function hereinafter described, one embodiment thereof is illustrated in F IG. 3 and comprises a housing means 102 having terminal means 103 and 104 respectively being adapted to be interconnected to the leads 67 and 73 as well as to the bimetal member 69 and fixed electrical contact 72, The opening means 44 in the conduit 42 can comprise a nipple means 105 threaded into a threaded bore 106 of the housing means 102 and being provided with a valve seat 107 adapted to be opened and closed by the valve member 78 carried on the bimetal member 69.

The nipple means 105 has a passage means 108 formed therein and leading to the valve seat 107, the passage means 108 also leading to passage means 109 formed in the housing means 102 that is adapted to be disposed in fluid communication with the conduit 42 whereby the valve seat 107 in FIG. 3 forms the opening means 44 in the conduit 42 of HO. 1.

Therefore, it can be seen that the various components of the control system 10 can be formed in a relatively simple and economical manner to operate in a unique manner now to be described.

When the control system 10 is in the "off position as illustrated in FIG. 1 so that the power source leads L and L are not interconnected across the points 52 and 53, the chambers 23, 30 and 36 of the actuators 28, 25 and 32 are at atmospheric condition because of the opened opening means 43, 44 and 48 in the conduits 41, 42 and 46 whereby the valve member 22 is held against the valve seat 14 and the valve member 29 is held against the valve seat 15 while the shaft valve member 17 is to its extreme right position to hold open the valve seat 16 in its maximum effective opening position. in addition, the bimetal member 59 is sensing room temperature so that the contact 63 is held against the contact 64. Similarly, the bimetal member 69 is sensing that the igniter 66 is not at ignition temperature and that the burner means 11 does not have any flames whereby the contact 71.is held against the contact 72. However, the bimetal member 84 is sensing room temperature whereby its contact 87 is spaced from the contact 88. Therefore, the valve members 91 and 78 are respectively spaced from the opening means 43 and 44 in the conduit means 42 so that the atmosphere is fully interconnected to the chambers 23 and 30 of the actuators 18 and 25.

During the normal cycle of operation of the apparatus, suitable timer means or the like interconnects the power source leads L and L to the points 52 and 53 of the circuit means 51 when the burner means 11 is required to be operated. At this time, current flows from point 52 through lead 73 and closed switch means 58 to lead 67 so as to shunt the vacuum pump 38 from the power source leads L and L so that the vacuum pump 38 will not operate. The current in lead 67 passes through a parallel circuit to lead 61 and, thus, to power source lead L with one path of that parallel circuit being through the igniter 66 and closed switch means 56 and with the other path of that parallel circuit being through the series connected heater means 82 and 79 so that the heater means 79 and 82 begin to heat the respective bimetal switch blades 59 and 84. Since the igniter 66 is now being energized. the bimetal member 69 of the switch means 58 senses the temperature of the igniter 66 and will not move away from the contact 72 until the igniter 66 reaches its ignition temperature.

However, when the heater means 82 reaches a certain temperature before the igniter 66 reaches its ignition temperature,

the bimetal member 84 of the switch means 57 warps upwardly in FIG. 1 to not only close the valve member 91 against the opening 43 of the conduit means 42, but also to place the contact 87 against the contact 88 to shunt the heater means 82 from the circuit means 51 whereby the parallel path is now through the closed switch means 57 and heater means 79.

When the igniter 66 thereafter reaches ignition temperature, the bimetal member 69 of the switch means 58 moves to the right in FIG. 1 to move the contact 71 away from the contact 72 while closing the valve member 78 against the opening means 44 in the conduit 42 whereby the atmosphere is disconnected from the conduits 41 and 42 except through a controlled bleed means 110 in the conduit 41 for a purpose hereinafter described.

The opening of the switch means 58 causes the vacuum pump 38 to now be placed across the power source leads L and L so that the vacuum pump 38 begins to operate and evacuate the conduits 41 and 42 and, thus, the chambers 23 and 30 of the actuators 18 and 25 whereby, when the resulting pressure differential across the diaphragms 21 and 28 exceeds the force of the compression springs 24 and 31, the diaphragms 21 and 28 move upwardly to respectively open the valve seats 14 and 15 so that the fuel source conduit 12 is now interconnected to the burner means 11. The resulting flow of fuel out of the burner means 11 is now ignited by the igniter 66 whereby the flames now existing at the burner means 11 are sensed by the bimetal switch blade 69 so as to maintain the bimetal switch blade 69 away from the contact 72 and in a position to maintain the opening means 44 in the conduit 42 closed.

Since the heater means 82 of the switch means 57 has been previously dropped from the circuit means 51 by the closing of the switch blade 84 against the contact 88, the bimetal member 84 is no longer heated and will cool so as to tend to move back to the position illustrated in FIG. 1 except that the vacuum which has been previously created in the conduit 42 creates a pressure differential across the valve member 91 to maintain the valve member 91 in its closed position against the opening means 43 whereby the contact 87 also remains in electrical contact with the contact 88 as long as a vacuum condition exists in the conduit 42.

Because the vacuum pump 38 has now been placed in the circuit 51 across the points 52 and 53, the amount of current now flowing through the heater means 79 is not sufficient to raise the heater means 79 to a temperature which will cause opening ofthe switch blade 59 away from the contact 64.

However, if during the initial start up of the system when the energized igniter 66 reached ignition temperature to cause opening of the switch means 58 to place the vacuum pump 38 across the points 52 and 53 of the circuit 51 did not subsequently result in an ignition of the burner means 11, the energizing of the vacuum pump 38 would reduce the amount of current flowing through the igniter 66 so that the same would fall below ignition temperature and cause the switch blade 69 to return to the position illustrated in FIG. 1, whereby a greater amount of current would now flow through the heater means 79 such that after a predetermined time period of such energizing of the heater means 79, the switch blade 59 would warp upwardly to disconnect the contact 63 from the contact 64 and would remain open until the power source is subsequently cut off from the points 52 and 53 of the circuit means 51.

In this manner, the igniter 66 is dropped from the circuit so that the blade 69 of the switch means 58 holds the valve member 78 away from the opening means 44 in the conduit 42 whereby the actuators 18 and 25 return to atmospheric condition and close the valve members 22 and 29 so as to prevent fuel from issuing from the burner means 11.

During normal operation of the circuit means 10 after the burner means 11 has been ignited in the manner previously described, the vacuum pump 38 maintains the valve members 22 and 29 in their open position. However, the output of the vacuum pump 38 on the pressure side 45 thereof is directed through the conduit means 46 and will normally pass out of the opening means 48 of the branch conduit 47 so as to have no effect on the actuator 32.

The bimetal member 50 is so constructed and arranged that the same senses the temperature effect of burner means 11 so that when the burner means 11 exceeds a predetermined temperature effect, the bimetal member 50 warps to the right in FIG. 1 to cause the valve member 49 to decrease the effective size of the opening 48 in the branch conduit 47 so that increased pressure will be directed by the vacuum pump 38 into the chamber 36 of the actuator 32 to tend to move the diaphragm 35 to the left in opposition to the force of the compression spring 37. Therefore, as the temperature effect of the burner means 11 increases above a predetermined tempera ture effect, the pressure in the chamber 36 increases to move the valve member 17 closer to the valve seat 16 so as to decrease the flow of fuel passing into the burner means 11 whereby a modulating action of the valve member 17 tends to maintain the temperature effect of the burner means 11 at the desired temperature effect for the control system 10.

When the control circuit 51 disconnects the power source leads L and L from the points 52 and 53 to terminate the operation of the burner means 11, it can be seen that the vacuum pump 38 ceases to operate whereby the atmosphere can again return to the chambers 23 and 30 of the actuators 18 and 25 through the controlled bleed means so that the valve members 22 and 29 will close against the valve seats 14 and 15 to terminate the flow of fuel to the main burner means 11. The termination of flames at the burner means 11 is sensed by the bimetal member 69 of the switch means 58 to cause the switch means 58 to move back to the position illustrated in FIG. 1 whereby the valve member 78 is moved away from the opening means 44 and likewise the loss of pressure differential across the valve member 91 in the switch means 57 permits the bimetal member 84 thereof to move back to the open position illustrated in FIG. 1 so that the system 10 is again in a position for causing operation of the burner means 11 in the manner previously described.

Therefore, it can be seen that this invention not only provides an improved fuel control system for a fuel burning apparatus or the like, but also this invention provides an improved method of operating such an apparatus or the like.

While a modulation of the flow of fuel to the burner means 11 in the control system 10 has been described and illustrated as being provided by a pressure operated actuator 32, it is to be understood that the various features of this invention can be utilized to provide fuel flow modulation without utilizing the pressure operated actuator 32.

In particular, another control system of this invention is generally indicated by the reference numeral 10A in FIG. 4 and parts thereof similar to the control system 10 previously described are indicated by like reference numerals followed by reference letter A."

As illustrated in FIG. 4, the control system 10A is substantially identical to the control system 10 previously described except that the conduit 41A has a restriction 111 therein intermediate the actuator 18A and the conduit 40A. In addition, a minimum flow bypass port 112 is formed around the valve seat 15A for a purpose hereinafter described.

Also, the conduit means 42A leading to the actuator 25A in addition to the opening means 43A and 44A therein has a third opening means 113 that has its effective size varied by a valve member 114 carried by a bimetal member 115 that is adapted to sense the temperature effect of the burner means 1 1A.

The bimetal member 115 is so constructed and arranged that the same normally maintains the valve member 114 in a position to close the opening 113 but upon an increase in the temperature effect that is produced by the burner means 11A, the bimetal member 115 will warp to the left so that when the temperature effect of the burner means 11A exceeds the predetermined temperature effect, the opening means 113 is sufficiently open so that the valve member 29A is disposed in its closed position, as will be apparent hereinafter.

l0l027 Mrs Upon the initial start up of the system 10A, the ignition means 66A is energized in the manner previously described so that when the same reaches ignition temperature. the switch blade 69A snaps open to close the opening 44A as well as to cause the vacuum pump 38A to be energized. The energized vacuum pump 38A now evacuates to conduits 42A and 41A so that the valve members 22A and 29A move to their open positions to permit fuel to flow from the fuel source conduit 12A to the burner means 11A and be ignited by the ignition means 66A in the manner previously described.

However, when the temperature effect of the burner means 11A exceeds the predetermined temperature effect thereof, the bimetal member 115 has warped to the left a distance sufficient to cause a change in the vacuum condition in the chamber 30A of the actuator 25A so that the valve member 29A thereof is moved closer to the valve seat 15A to modulate the flow of fuel to the burner means 11A. Therefore, it can be seen that even if the valve member 29A is moved to its fully closed position as illustrated in FIG. 4, the restriction Ill in the conduit 41A maintains the valve member 22A in its open position while the port 112 permits a minimum flow of fuel to the burner means 11A to maintain combustion at the burner means 11A whereby the temperature effect of the burner means 11A will immediately fall to cause the bimetal member 115 to again move to the right and permit the valve member 29A to move further to an open position thereof.

Therefore, it can be seen that both systems 10 and 10A of this invention are uniquely arranged in such a manner that the pneumatic source creating device 38 or 38A thereof will not be energized until the ignition means 66 or 66A reaches ignition condition. Further, the systems 10 and 10A each provides opening means 44 or 44A in the conduit means leading from the vacuum source creating means 38 or 38A to the pneumatically operated actuators that remain open to the atmosphere until the ignition means 66 or 66A reaches ignition temperature so that the switch means 58 and 58A can close such opening means 44 or 44A.

In this manner, a safe and accurate fuel control system and method of operating the same are provided by this invention.

What is claimed is:

1. ln a fuel control system having pneumatically operated actuator means for interconnecting a source of fuel to a burner means when a pneumatic source is interconnected to said actuator means, the improvement comprising an electrically operated pneumatic source creating device that only creates said pneumatic source when said device is interconnected to an electrical power source, electrically operated ignition means for said burner means, and electrical circuit means operatively interconnected to said igniting means and to said device to operate the same, said circuit means having electrical switch means which will operate said source creating device by interconnecting said electrical power source thereto to actuate said actuator means only when said circuit means has interconnected said electrical power source to and has operated said ignition means to ignition temperature for igniting said burner means, said pneumatic source creating device comprising an electrically operated pneumatic pump.

2. ln a fuel control system having pneumatically operated actuator means for interconnecting a source of fuel to a burner means when a pneumatic source is interconnected to said actuator means, the improvement comprising an electrically operated pneumatic source creating device, electrically operated ignition means for said burner means, electrical cir cuit means operatively interconnected to said ignition means and to said device to operate the same, said circuit means having electrical switch means which will operate said source creating device to actuate said actuator means only when said circuit means operates said ignition means to ignition temperature for igniting said burner means, and passage defining means leading from said pneumatic source creating device to said actuator means, said passage defining means having opening means adapted to interconnect said passage defining means to the atmosphere to prevent the actuation of said ac tuator means, said circuit means having valve means operated thereby to close and open said opening means.

3. ln a fuel control system as set forth in claim 2, said switch means operating said valve means to only close said opening means when said circuit means operates said ignition means to ignition temperature.

4. in a fuel control system as set forth in claim 2, said circuit means having a temperature sensor operating said valve means;

5. in a fuel control system as set forth in claim 4, said temperature sensor comprising a bimetallic member.

6. In a fuel control system as set forth in claim 5. said bimetallic member also operating said switch means.

7. In a fuel control system as set forth in claim 6, said bimetallic member being electrically conductive and forming part of the circuit path of said circuit means.

8. In a fuel control system having pneumatically operated actuator means for interconnecting a source of fuel to a burner means when a pneumatic source is interconnected to said actuator means, the improvement comprising an electrically operated pneumatic source creating device, electrically operated ignition means for said burner means, electrical circuit means operatively interconnected to said ignition means and to said device to operate the same, said circuit means having electrical switch means which will operate said source creating device to actuate said actuator means only when said circuit means operates said ignition means to ignition temperature for igniting said burner means, and passage defining means leading from said pneumatic source creating device to said actuator means, said passage defining means having opening means adapted to interconnect said passage defining means to the atmosphere, and valve means for controlling the effective size of said opening means to vary the degree of actuation of said actuator means and thus vary the degree of flow of fuel from said source of fuel to said burner means.

9. In a fuel control system as set forth in claim 8, said valve means being temperature responsive to increase the effective size of said opening means on an increase in temperature.

10. In a fuel control system as set forth in claim 8, said valve means being temperature responsive to decrease the effective size of said opening means on an increase in temperature.

11. In a fuel control system having pneumatically operated actuator means for interconnecting a source of fuel to a burner means when a pneumatic source is interconnected to said actuator means, the improvement comprising passage defining means interconnecting said pneumatic source to said actuator means and having opening means for interconnecting said passage defining means to the atmosphere to prevent the actuation of said actuator means, electrically operated ignition means for said burner means, and valve means for opening and closing said opening means, said valve means having sensing means so as to only initially close said opening means when said ignition means reaches ignition temperature so as to initially interconnect said pneumatic source to said actuator.

12. In a fuel control system as set forth in claim 11, said sensing means of said valve means maintaining said valve means in its closed position when sensing flame means at the ignited burner means.

13. In a fuel control system as set forth in claim 12, said sensing means comprising a bimetallic member.

14. In a fuel control system as set forth in claim 12, said pneumatic source comprising a vacuum source.

15. In a fuel control system as set forth in claim 1!, said valve means having an electrical contact movable therewith.

I6. ln a method for operating a fuel burner means that has a source of fuel interconnected thereto when pneumatically operated actuator means is interconnected to a pneumatic source, the improvement comprising the steps of first energizing an electrical ignition means for said burner means to ignition temperature, and, thereafter, automatically creating said pneumatic source to actuate said actuator means by automatically turning on a pneumatic pump so that fuel can issue from said burner means and be ignited by said ignition means whereby said pneumatic source cannot be created until said ignition means reaches ignition temperature.

17. In a method as set forth in claim 16, said step of creating said pneumatic source comprising the step of electrically energizing an electrically operated pneumatic pump.

18. In a method as set forth in claim 17, said step of creating said pneumatic source comprising the step of electrically energizing said pump by the closing of an electrical switch that senses the temperature of said ignition means.

19. In a method for operating a fuel burner means that has a source of fuel interconnected thereto when pneumatically operated actuator means is interconnected to a pneumatic source, the improvement comprising the steps of first energizing an electrical ignition means for said burner means to ignition temperature, thereafter, automatically creating said pneumatic source to actuate said actuator means so that fuel can issue from said burner means and be ignited by said ignition means whereby said pneumatic source cannot be created until said ignition means reaches ignition temperature, and automatically closing an opening means in the passage defining means that interconnects the pneumatic source to said actuator means only after said ignition means reaches ignition temperature whereby until the opening means is closed, the pneumatic source can not actuate said actuator means.

20. In a method as set forth in claim 19, said step of automatically creating said pneumatic source and said step of automatically closing said opening means being performed by the same element that senses the temperature of said ignition means.

* i i i i 

1. In a fuel control system having pneumatically operated actuator means for interconnecting a source of fuel to a burner means when a pneumatic source is interconnected to said actuator means, the improvement comprising an electrically operated pneumatic source creating device that only creates said pneumatic source when said device is interconnected to an electrical power source, electrically operated ignition means for said burner means, and electrical circuit means operatively interconnected to said igniting means and to said device to operate the same, said circuit means having electrical switch means which will operate said source creating device by interconnecting said electrical power source thereto to actuate said actuator means only when said circuit means has interconnected said electrical power source to and has operated said ignition means to ignition temperature for igniting said burner means, said pneumatic source creating device comprising an electrically operated pneumatic pump.
 2. In a fuel control system having pneumatically operated actuator means for interconnecting a source of fuel to a burner means when a pneumatic source is interconnected to said actuator means, the improvement comprising an electrically operated pneumatic source creating device, electrically operated ignition means for said burner means, electrical circuit means operatively interconnected to said ignition means and to said device to operate the same, said circuit means having electrical switch means which will operate said source creating device to actuate said actuator means only when said circuit means operates said ignition means to ignition temperature for igniting said burner means, and passage defining means leading from said pneumatic source creating device to said actuator means, said passage defining means having opening means adapted to interconnect said passage defining means to the atmosphere to prevent the actuation of said actuator means, said circuit means having valve means operated thereby to close and open said opening means.
 3. In a fuel control system as set forth in claim 2, said switch means operating said valve means to only close said opening means when said circuit means operates said ignition means to ignition temperature.
 4. In a fuel control system as set forth in claim 2, said circuit means having a temperature sensor operating said valve means.
 5. In a fuel control system as set forth in claim 4, said temperature sensor comprising a bimetallic member.
 6. In a fuel control system as set forth in claim 5, said bimetallic member also operating said switch means.
 7. In a fuel control system as set forth in claim 6, said bimetallic member being electrically conductive and forming part of the circuit path of said circuit means.
 8. In a fuel control system having pneumatically operated actuator means for interconnecting a source of fuel to a burner means when a pneumatic source is interconnected to said actuator means, the improvement comprising an electrically operated pneumatic source creating device, electrically operated ignition means for said burner means, electrical circuit means operatively interconnected to said ignition means and to said device to operate the same, said circuit means having electrical switch means which wiLl operate said source creating device to actuate said actuator means only when said circuit means operates said ignition means to ignition temperature for igniting said burner means, and passage defining means leading from said pneumatic source creating device to said actuator means, said passage defining means having opening means adapted to interconnect said passage defining means to the atmosphere, and valve means for controlling the effective size of said opening means to vary the degree of actuation of said actuator means and thus vary the degree of flow of fuel from said source of fuel to said burner means.
 9. In a fuel control system as set forth in claim 8, said valve means being temperature responsive to increase the effective size of said opening means on an increase in temperature.
 10. In a fuel control system as set forth in claim 8, said valve means being temperature responsive to decrease the effective size of said opening means on an increase in temperature.
 11. In a fuel control system having pneumatically operated actuator means for interconnecting a source of fuel to a burner means when a pneumatic source is interconnected to said actuator means, the improvement comprising passage defining means interconnecting said pneumatic source to said actuator means and having opening means for interconnecting said passage defining means to the atmosphere to prevent the actuation of said actuator means, electrically operated ignition means for said burner means, and valve means for opening and closing said opening means, said valve means having sensing means so as to only initially close said opening means when said ignition means reaches ignition temperature so as to initially interconnect said pneumatic source to said actuator.
 12. In a fuel control system as set forth in claim 11, said sensing means of said valve means maintaining said valve means in its closed position when sensing flame means at the ignited burner means.
 13. In a fuel control system as set forth in claim 12, said sensing means comprising a bimetallic member.
 14. In a fuel control system as set forth in claim 12, said pneumatic source comprising a vacuum source.
 15. In a fuel control system as set forth in claim 11, said valve means having an electrical contact movable therewith.
 16. In a method for operating a fuel burner means that has a source of fuel interconnected thereto when pneumatically operated actuator means is interconnected to a pneumatic source, the improvement comprising the steps of first energizing an electrical ignition means for said burner means to ignition temperature, and, thereafter, automatically creating said pneumatic source to actuate said actuator means by automatically turning on a pneumatic pump so that fuel can issue from said burner means and be ignited by said ignition means whereby said pneumatic source cannot be created until said ignition means reaches ignition temperature.
 17. In a method as set forth in claim 16, said step of creating said pneumatic source comprising the step of electrically energizing an electrically operated pneumatic pump.
 18. In a method as set forth in claim 17, said step of creating said pneumatic source comprising the step of electrically energizing said pump by the closing of an electrical switch that senses the temperature of said ignition means.
 19. In a method for operating a fuel burner means that has a source of fuel interconnected thereto when pneumatically operated actuator means is interconnected to a pneumatic source, the improvement comprising the steps of first energizing an electrical ignition means for said burner means to ignition temperature, thereafter, automatically creating said pneumatic source to actuate said actuator means so that fuel can issue from said burner means and be ignited by said ignition means whereby said pneumatic source cannot be created until said ignition means reaches ignition temperature, and automatically closing an opening means in the passage defining means that inteRconnects the pneumatic source to said actuator means only after said ignition means reaches ignition temperature whereby until the opening means is closed, the pneumatic source can not actuate said actuator means.
 20. In a method as set forth in claim 19, said step of automatically creating said pneumatic source and said step of automatically closing said opening means being performed by the same element that senses the temperature of said ignition means. 